In my opinion it's way too early to conclude that Romney's fund raising video is a "game changer". While Romney's comments are reprehensible, the media coverage so far does not parse the victims to include the 50% of Republicans in red states who are low income and don't pay taxes---but distributes 100% of these folks to the Obama camp. Thus, on the media surface, Romney was correct. A lot of people pay no federal income taxes and they all vote for Obama. What else is new?
I am not impressed by the way Democrats are addressing the video. Democrats have not properly responded to the "47% pay no taxes" charge in the past and I can't see that their response to this video so far has improved their messaging. So to turn this video into a game changer, Democrats need to improve their attacks. "Romney wrote off the 47%" doesn't, imo, move the needle.